Contemporary nail clippers comprise a pair of elongate diverging blade arms joined together at one end. Concave blades are formed in the other ends of the blade arms. A lever arm is mounted on a post that passes through holes formed in the spaced apart ends of the arms. The holes lie along the longitudinal axes of the blade arms. Nail clipping action is produced by appropriately orienting the lever arm and, then, manually moving the lever arm toward the adjacent blade arm. The result of this action moves the blade arms together and creates a chop-type cutting action. More specifically, after a nail is placed between the blades, a force is applied to the lever arm causing the lever arm to move toward the adjacent blade arm. As the force applied to the lever arm increases the blade arms are drawn together. As a result, the gap between the blades is closed. As the gap closes, the blades first move to the point where they encounter the nail. At this point, blade movement temporarily halts due to the resistance to cutting produced by the nail. Thereafter, as greater force is applied to the lever arm, the blade arm adjacent the lever arm begins to bow. A point is finally reached where the inertial energy stored in the bowed blade arm is adequate to force the blades to chop through the nail. When the blades begin to penetrate the nail, they gain momentum. This momentum increases until the blades finally bite through the nail with an explosive force. Examples of chop-type nail clippers that function in the foregoing manner are described in U.S. Pat. Nos. 2,774,138; 3,042,047; 3,088,204; and 3,189,996.
The force produced when the blades finally penetrate through the nail creates the four major disadvantages of prior art nail clippers. First, when the blades bite together at a high force level a loud "snap" occurs. The snap is caused by high-energy vibration in the metal, with a subsequent vibration of the surrounding air molecules and, hence, acoustic propagations through the air. It has been found that the resulting high-pitched snap is offensive to many people. In fact, it is so offensive that many people refuse to use prior art nail clippers for this reason alone. Such individuals tend to use less effective, and more expensive, cutting devices, such as small scissors and files, to trim their nails. While, per se, the high-pitched snap is normally not objectionable to other people, even such people become annoyed by the snapping action when it occurs in certain environments, namely public places.
In addition to the undesirable high-pitched "snap", prior art nail clippers have the disadvantage of randomly projecting nail fragments in a wide variety of directions. More specifically, as noted above, prior art nail clipper blades finish a cut with an explosive force. The explosive force propels nail fragments through the air in random directions. This result is particularly undesirable to fastidious people concerned about cleanliness, as the nail debris is scattered in clothing, carpeting, and places other than a waste receptacle. This disadvantage renders conventional chop-type clippers both annoying and unsanitary. It is unsanitary because nail beds are excellent sites for bacterial proliferation.
Further, the high-energy impact of the blade edges against one another rapidly dulls the blades. As a result, greater and greater force on the lever arm is required to cut nails efficiently as prior art nail clippers become duller and duller with use. As they become duller, frequently, prior art chop-type nail clippers produce a cutting force that is inadequate to cut thick or calcified nails.
Another disadvantage of prior art chop-type nail clippers is their tendency to split or crack brittle and polished nails. This result also occurs because of the sudden, high-force cutting action produced by contemporary nail clippers.
As an alternative to chop-type nail clippers, U.S. Pat. No. 846,924 proposes a nail clipper having jaws that close in an overlap shear cut manner. The major disadvantage of this relatively ancient proposal is a complicated mechanism used to accomplish the desired type of cut.
Therefore, it is an object of this invention to provide a new and improved nail clipper.
It is a further object of this invention to provide an uncomplicated nail clipper that cuts nails quietly, i.e., without a high-pitched snap.
It is another object of this invention to provide an uncomplicated nail clipper that does not propel nail debris in random directions as nails are clipped.
It is yet another object of this invention to provide a nail clipper that does not produce a high explosive force that tends to rapidly dull the blades of the nail clippers.
It is yet another object of this invention to provide a new and improved nail clipper that is ideally suited for clipping brittle and polished nails with a minimal amount of splitting or cracking of the nail or the material with which the nail is coated.